Is there something wrong with my Edge 1030 screen?

Have you checked the display settings: www8.garmin.com/.../GUID-0222B83B-39C2-4537-9A4D-AD8688F2CD26.html.

If you mean the brightness etc then the 1030 is on full brightness and the 1000 on Auto. 

Day/Night mode on both units are set to auto. Changing the 1030 to day made no difference.

Don't compare the screens indoors. Take them outside in full bright sunlight and check again

I also had the same impression as yours when I purchased my 1030. But once I got used to it, I don't even notice it anymore. This appearance is also due to the automatic setting of the screen brightness depending on the amount of ambient light. One of the advantages is the good battery savings you will get. Do not worry.

If I take a screenshot on the Edge 1030 it shows the colours brighter than they actually are...

Colors on computers are represented by numbers. The numbers in the screen shot are the same as being displayed on the screen. The problem is that different displays show those colors differently. The Garmin screens (any of them) are not very accurate displays. Part of that is because they are transreflective (they don't need a backlight).

Part of the difference between the two Edges appears to be a difference in backlight intensity. Some of it is due to the screens being different. Your 1030 seems similar to mine (I've had two).

Edge 1030 screen is
-indoor: worse than Edge 1000: muddy; dull; faded
-outdoor especially in bright sun: much better that Edge 1000!

Thanks guys, I was afraid I'd bought a duff unit. I still have my doubts about. The owner didn't know much about it and even said it was battery under the door on the back. It took ages to get a GPS lock although he said he only used it inside on his turbo. I asked if it had been dropped at all and he assured me it hadn't. When I got it home and went to fit the mount I discovered a broken part of the Garmin mount in the mount. The male part of the Garmin isn't broken. I sent a message asking if the back had ever been replaced (this is what got me thinking there was a fault with the screen) and he said no. 

The  technology used on the 1030 is not like a phone display. It is meant to work well in direct sunlight and use very little power. The resulting colours are washed out but that is no problem given the use of the device. The pictures taken from the website are certainly not representative - they were improved quite certainly. 

Agree with the comments on the display - 1030 colors look faded, but the screen is perfectly legible outside, and that's exactly what you are looking for on a bike. You're not going to read fashion e-magazines on it...

I wouldn't worry about the mount on your 1030 since that seems to be in good shape still. The loose part probably broke off another 1030 and was still stuck in the mount... Hard to believe though that this unit was used inside only, telling from the dirt around the mount. I've been using mine for 15,000km on the streets and it's still clean (good weather rides mostly plus I take good care).

Anyway, if it works, use it and be happy with it, assuming you got a decent discount vs a new unit...

PS: I don't get the argument with the GPS...